1. Field of the Invention
This invention relates to a video printer for transforming video signals into an image and printing the transformed image on a transfer sheet.
2. Description of the Prior Art
The conventional video printer, as it is so-called, is mainly comprised of an image memory for fixedly holding an image during a recording operation, a gradation control section, a transfer unit for transferring a transfer sheet etc. and a recording medium. In distinction from a printer other than the video printer mainly aimed at drawing an ordinary letter or a delineating a drawing, the video printer features analog expression of the gradation because the image recorded is a natural image.
The video printer is classified into, for example, an ink jet system printer, a thermal transfer type printer and a silver halide type printer. With the thermal transfer type printer, for example, a transfer sheet comprised of an imaging sheet and a base film coated with ink is pressed between a printing drum and a thermal head and an electric energy applied to the thermal head during rotation of the printing drum is controlled depending on the amplitude of the image signals for expression of the gradation. A line head is frequently employed as the thermal head because of ease in pixel positioning and recording time reduction. Video signals are supplied to such video printer from e.g. a video camera.
Usually, a roll-shaped heat-sensitive sheet is employed as the transfer sheet in the above-mentioned thermal transfer type video printer.
Meanwhile, in the above-described conventional video printer, the transfer sheets 120 (roll sheets 122) are cut by a cutter 133 provided at a rectangular opening of a video printer casing (operating panel), as shown in FIG. 1.
Besides, with the video printer, the distance C between the cutter 133 and a heater 131 of a thermal head 130, for example, cannot be reduced to zero, because of mechanical constraints.
Thus, when the transfer sheet 120 having the image printed thereon is severed by cuter 133, a margin corresponding to the distance between the severing position by the cutter 133 and the printing start position by the thermal head 130 or heater 131, that is the margin corresponding to the distance C, is necessarily produced in the printed transfer sheet 120. That is, the amount a of the margin between a portion 121 of the transfer sheet 120 having the image printed thereon and the severed position amounts to, for example, 20 to 30 mm.
Consequently, the number of sheets of the roll-shaped transfer sheet 120 (roll sheets 122) that can be printed by each roll is diminished because of the presence of the margin. Meanwhile, this number is on the order of e.g. 205 per 20 m-long transfer sheet roll, in the case of a conventional video printer.
Besides, in the above-described conventional video printer, the transfer sheet 120 (roll sheet 122) is severed by the cutter 133 provided at the rectangular opening provided on the front surface of the video printer casing, that is the opening in the operating panel, as shown in FIG. 3.
On the other hand, it is not possible with the video printer to reduce the distance C between the position of the cutter 133 and the heater 131 of the thermal head 130 to zero because of mechanical constraints.
Thus, when the transfer sheet 120 having the image printed thereon is severed by cutter 133, a margin corresponding to the distance between the severing position by the cutter 133 and the printing start position by the thermal head 130 or heater 131, that is the margin corresponding to the distance C, is necessarily produced in the printed transfer sheet 120.
In other words, if plural images are to be printed on the transfer sheet 120, the severing margin is necessarily provided between neighboring image printing units on the transfer sheet 120 (between neighboring image portions).
Consequently, the number of sheets of the roll-shaped transfer sheet 120 (roll sheets 122) that can be printed by each roll is diminished because of the presence of the margin. Meanwhile, this number is on the order of e.g. 230 per 20 m-long transfer sheet roll, in the case of a conventional video printer.
Besides, when printing an image on a transfer sheet by the above-described video printer, a print mode is selected from a variety of modes indicating a variety of functions of the video printer, and a print start key, provided on an operating panel of the video printer, is turned on to carry out the printing.
In addition, with the above-described video printer, video data stored in and read out from the image memory to enable plural printed sheets to be made from the same image. When making plural printed sheets of the same image, it is necessary to specify the number of sheets to be printed after selection of the print mode.
Thus, if, with the above-described conventional video printer, it is desired to obtain plural printed sheets from an image stored in the image memory, or if the number of sheets to be printed was set in an incorrect manner, it is necessary to repeat the operations of selecting the print mode, specifying the number of sheets to be printed and turning on the print start key, which means a troublesome and time-consuming operation.
Besides, with a majority of conventional video printers, the contents of the operating mode or the number of sheets to be printed etc. may be confirmed by display means, such as a liquid crystal display.
However, it is desirable to reduce the size of the video printer in view of ease in transportation and the spatial utilization efficiency, such that provision of the display means, such as LCDs, is unfavorable from the standpoint of size reduction.